**1. Introduction**

Improving power supply efficiency from private homes to large industrial enterprises is an urgent and difficult task for power supply (PS) enterprises. This is because power supply companies often encounter problems such as the remoteness of energy consumers from power distribution points, insufficient capacity margin, depreciation of power supply equipment, and the lack of specialists involved in servicing this equipment. As a result, it leads to the increase in the number of equipment failures and the increase in PS interruptions. In turn, this translates into losses for power supply companies due to the elimination of the failure's consequences and for consumers due to a disruption of the technological process caused by the power supply outages.

This article deals with the analysis of power supply restoration after power line failures. Thus, the organization of the article is as follows. Section 2 is a literature review of the state of the art with the

motivation and contribution of this paper. Section 3 introduces the problem of power supply reliability. It indicates the elements that have an impact on the total time of restoration. In Section 4, the calculation of each element is performed based on real data obtained from a Russian power supply company. Section 5 contains a discussion of the results and propositions for the technical means of automation of electrical networks to reduce the power supply restoration time. Section 6 is the conclusion part.
